Bicycle frame



FIG. 1 is a right side elevation view of a bicycle frame showing our new design, the broken lines are for illustrative purposes only and form no part of the claimed design;

FIG. 2 is a perspective view of a bicycle frame showign our new design;

FIG. 3 is a right side elevation view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a front end view thereof; and,

FIG. 7 is a back end view thereof. 

The ornamental design for a bicycle frame, as shown and described. 